Approximately 1.1 million deaths each year are a result of emboli from carotid artery atherosclerosis. These deaths are highly preventable through lifestyle changes or drug therapy if the development of atherosclerosis is detected prior to plaque formation. Similarly, interventional treatment and therapy is available with good clinica efficacy at later stages of the disease if carotid plaques can be adequately characterized (i.e. vulnerable versus stable plaques). Ultrasound-based targeted molecular imaging represents an emerging technology with potential to provide both earlier detection of carotid atherosclerosis and more specific diagnosis and characterization of carotid plaques. However, current use of microbubble-based ultrasound imaging in the clinic is limited to a narrow set of indications (e.g. liver nodule diagnosis) and current clinical use of targeted microbubble imaging is non-existent largely due to technical challenges associated with imaging in large arteries. The overarching goal of this project is to break down the technological barriers currently preventing clinical utilty of ultrasound-based targeted molecular imaging for prevention of stroke. Successful achievement of this goal will involve in vivo demonstration of a novel targeted molecular imaging technology, called singular spectrum-based targeted molecular (SiSTM) imaging, with greater than 95% sensitivity and specificity for detection of early molecular markers for atherosclerosis in rabbit aorta arteries. Beam sequences specific to SiSTM imaging will be optimized for enhanced sensitivity and specificity including an adaptive blood velocity correction technique. Additionally, a dual frequency 1.5D molecular imaging probe will be designed, fabricated, and implemented on a research scanner. In vivo sensitivity and specificity of SiSTM imaging in large arteries will be assessed using Watanabe heritable hyperlipidemic strain (WHHL) rabbits exhibiting genetic predisposition for extreme hypercholesterolemia and advanced atherosclerosis. Immunohistochemistry results for disease markers will be correlated with SiSTM imaging data.